About the Lack of Warming…

It’s common knowledge among those who follow such things that global temperatures have not gone up very much in the past several years. This has caused many to believe that the recent lack of warming contradicts what climate models say should happen in response to the increasing Tyndall gases. This, in turn, has provoked the counterargument that the Earth is still warming, just on a longer time scale, or that the recent period is too short to yield statistically significant results.

These counterarguments are not compelling. Fundamentally, any change in global temperature, even if it’s just from one year to another, must have a cause. Saying that we need to look at longer time scales denies the need to find the cause of the actual global temperature changes (or lack thereof) at shorter time scales.

Such causes have been sought, and a few papers have proposed various combinations of cloud cover, volcanic aerosols, the El Niño/Southern Oscillation (ENSO), deep ocean heat uptake, and so forth. A recent paper I like by Foster and Rahmsdorf (discussed here and here) takes a statistical approach to attempt to eliminate the effect of the other known forcing mechanisms, and what’s left over is a fairly steady warming. Others have noted, more casually, that 2011 was the warmest La Niña year on record.

I decided to take a simple approach at looking at the effect of ENSO. Using GISTemp Land/Ocean Index values and Niño 3.4 values, I computed 12-month running averages of Niño 3.4 and compared them to the average GISTemp values at lags of 0, 3, and 6 months. Foster and Rahmsdorf used a diferent ENSO index and found optimal lags between 2 and 5 months. So one would guess that a 3-month lag would fit the data best in my case, and indeed it did.

The normal threshold for El Niño or La Niña, as applied by the Climate Prediction Center, is for five consecutive months of at least 0.5 C above or below normal in a key region of the tropical Pacific. For working with annual data, I decided to call an annual average above 0.5 C an El Niño and an annual average below -0.5 C a La Niña. Then I plotted it up, color-coding each year for whether it was El Niño, La Niña, or neither (neutral). Here’s the result:

GISTemp global temperatures, 1951-2011

We see the latter half of the mid-century flat period, followed by the warming since 1970 and the relatively flat recent few years. We also see a few years that were exceptionally cold and whose timing fits with the known injection of aerosols into the stratosphere by the mighty volcanic eruptions of Agung and Pinatubo. It’s easy to see that both of these eruptions caused global temperatures to drop by about 0.3 C temporarily before recovering as the aerosols settled out of the stratosphere over the following 2-3 years. Finally, we see that, as is well known, La Niña years tend to be globally cold years and El Niño years tend to be globally warm, with a global lag of three months as mentioned earlier. And, we see that in a head-to-head match between El Niño and Pinatubo, Pinatubo wins.

To dig deeper, I’ll zoom in on the period since Agung. This isolates the period of nearly steady warming since 1970 and lets us focus a bit more on what has happened since 1998 or so. Here’s the chart:

GISTemp global temperatures from 1967 to present

Somehow, it no longer appears that global temperatures have leveled off in the past decade. That is because, with the color coding according to the phase of ENSO, the eye is able to compare apples to apples: the upward long-term trend during El Niño years (red triangles) is plain, the upward long-term trend during neutral years (green squares) is plain, and the upward long-term trend during La Niña years (blue diamonds) is plain.

Stare hard enough, though, and you see that they have leveled off. The last ten data points have little or no trend. But we see that the lack of trend is at least partly due to the El Niño year near the beginning of the 10-year period and the two La Niña years near the end.

Let’s get quantitative about this. In this case, with the temperature rise being nearly linear, it helps to add trendlines. I’ve excluded the three Pinatubo years from the regressions. Here’s the result:

GISTemp global temperatures, with trends for El Niño, neutral, and La Niña years computed separately. Pinatubo years are excluded.

There aren’t that many full-blown El Niño events, but theyglobal temperatures during El Niños seem to be following a steady upward trend. There are more La Niña events, and they toothose global temperatures also clearly follow a steady upward trend. Finally, the temperatures during the many neutral years also soshow no sign of departing from a steady upward trend. There’s enough scatter in the neutral years that if one had considered the period 1977-1987, or the period 1987-1997, one might be tempted to say that the neutral years had little or no warming. But the past decade fits nicely with the long-term upward trend of 0.16 C/decade shown by all three time series. [Clarifications added 4/30/2012. – John N-G]

The spacing between the lines is a good measure of the impact of El Niño and La Niña. All else being equal, an El Niño year will average about 0.2 C warmer globally than a La Niña year. Each new La Niña year will be about as warm as an El Niño year 13 years prior.

So we see a couple of recent La Niñas have caused the recent global temperature trend to level off. But be honest: doesn’t it seem likely that, barring another major volcanic eruption, the next El Niño will cause global temperatures to break their previous record? Doesn’t it appear that whatever has caused global temperatures to rise over the past four decades is still going strong?

So about that lack of warming: Yes, it’s real. You can thank La Niña.

As for whether this means that Tyndall gases are no longer having an impact: Nice try.

52 Responses

It seems like the La Nina years are much better defined in contrast to the neutral years than the El Nino years are (with the exception of the mighty ’98)… backed up by the fact that your neutral regression is closer to the El Nino line than to the La Nina line… is there an explanation? (eg, that the La Ninas were stronger, or that we expect La Nina to have a bigger effect on global mean temp, or that the warmer neutral years had Nino 3.4 averages that were only just below 0.5, or…?)

[M3: I noticed that too. There does seem to be a nonlinear relationship between the Nino 3.4 index and global temps. Don’t know if applies to MEI or other metrics of ENSO. – John N-G]

Also, this really sets Pinatubo and Agung off nicely. Over at WUWT Eschenbach was trying to persuade the crowd that you couldn’t see the volcanic effects, because the volcanic years were no cooler than normal years. (including, in his estimation, the “year without a summer”). But, as always in climate science, every observed effect is the result of a number of underlying causes, and there is rarely such a strong force that it completely dominates… (the year-over-year increase of CO2 is as close to an exception as I can think of, but even that evidence is doubted by the truly determined contrarians)

2. Hadley CRU3 shows less that 0.2C variation over the last 15 years. I’ve heard (not seen) that an “upward adjustment” due to either addition or re-weighting of polar stations was the rationale, and a similar “adjustment” was performed by GISS (who I believe did it first). Are these the new (most recent) GISS figures?

[Tom- Latest and greatest. Downloaded yesterday. The main historical difference between GISS and CRU was that CRU did not estimate arctic temperature anomalies. – John N-G]

3. The Keeling curve “sawtooth” clearly shows biota sensitivity in the atmosphere while the overall trend appears bereft of even a hint of La Niña or El Niño. This would imply that CO2 is well mixed oceanically; mixed well enough so that Sea Surface temperature signals also have a hard time showing up, but outgassing due to a generally warming ocean still is the main (slightly AGW augmented) source for atmospheric CO2.

4. Albedo influenced land temperatures however, will stay in a “leveling off” mode, with a few El Niño hiccups and Arctic re-freezing episodes making things interesting. Ocean lag will keep the “warmists” ((AGW and other) happy as the upward trend will continue, but leveling surface temps will likely take the wind out of the AGW sails (PI) for the “average blokes,” and perhaps in our lifetime (if we’re lucky), increasing albedo fueled by an open Arctic, will herald the first signs of rising sea temperature trend reduction, taking CO2 on a lower trajectory too, along with Sea-Levels!

Tomwys, I just have to ask, and I hope someone finally can give me a coherent answer:
You state in point 3 that the increase in atmospheric CO2 is due to ocean outgassing. If I understand that correctly, could you please, please, please tell me the sink that currently absorbs at the very least 30 gigatons of CO2 a year in the last decade? Or more than 1000 (yes, that’s a 1 with three zeros) gigatons of CO2 over the last century?

Note that this is really the low end: I assumed almost 50-50% of ocean outgassing and anthropogenic contribution in that 30 Gt/y number.

there is a growing divergence between the surface analyses and the lower tropospheric temperature anomaly data. We attribute a signficant part of the warm surface temperature bias to the land mimimum temperatures.

[Roger- I’ll run the numbers in a couple of days when I’m back in town. – John N-G]

Roger Pielke Sr.
“there is a growing divergence between the surface analyses and the lower tropospheric temperature anomaly data. We attribute a signficant part of the warm surface temperature bias to the land mimimum temperatures”

I will reserve my judgement until the NOAA analysis of lower troposphere is released (they’re working on it). They’ve identified some biases in the UAH and RSS analysis which have been shown to influence the trends at other altitudes in the atmosphere meaning that it is probably going to influence the synthetic lower tropospheric altitude.

Even if the number of supernovas in our neck of the galaxy influences climate, it’s not THE cause of long term changes in global climate. Other factors such as Milankovitch cycles are already known and supported by better evidence than the new paper being promoted by Anthony Watts.

And Watts is wrong when he says “Some geoscientists want to blame the drastic alternations of hot and icy conditions during the past 500 million years on increases and decreases in carbon dioxide, which they explain in intricate ways.” I don’t know of anyone who claims that Tyndall gasses drive all of the Earth’s long term climate change.

John –
This is an interesting analysis and one which I find more compelling than Foster and Rahmsdorf since it doesn’t require questionable adjustments to the temperature data but rather uses the data as is and just segregates it based on the three defined categories. Thank you for also stating that even year-to-year changes have a cause, which is much better than the unfortunate use of the term “noise” to describe interannual variability.

Let me make it a chorus of praise for your last graph! The simplicity and clarity of its message is truly amazing. So much so that when I saw it first, I more or less assumed that you had run just one regression with time and separate el nino and la nina dummy variables, and somehow plotted the three year-temp regimes from the model results. I just couldn’t believe their slopes would be that close to being equal. So I did the natural thing and downloaded the GISTemp and ONI data, took the annual temp mean and lagged the ONI by 3 months and ran my own regressions (omitting 1991-1993 as you did). And I also plotted them in Stata. And it is *still* kind of hard for me to believe that they are so close, but of course they are as I’ve the raw regression results as well as the graphic.

This was a very good idea of yours to plot the separate three types of years. I’m going to play around with some regional temp data in the same mode, thanks to your good idea. Congratulations.

Hi John- I asked John Christy to respond to the comment by rw who wrote above

“Roger Pielke Sr.
“there is a growing divergence between the surface analyses and the lower tropospheric temperature anomaly data. We attribute a signficant part of the warm surface temperature bias to the land mimimum temperatures”

I will reserve my judgement until the NOAA analysis of lower troposphere is released (they’re working on it). They’ve identified some biases in the UAH and RSS analysis which have been shown to influence the trends at other altitudes in the atmosphere meaning that it is probably going to influence the synthetic lower tropospheric altitude.”

John responded with

“We examined the NOAA (STAR) analysis and there is a noticeable problem with their method (attached). In every comparison with independent data, STAR was the hottest for MT (Table 4) and clearly had more error than UAH for both US and Australian station-by-station comparisons (Table 2 and Table 3). In the latest STAR TMT, there is also a spurious jump on 1 Jan 2001 that no other dataset has – a processing glitch evidently.

That’s a pretty tight grouping (+/- 0.025 from mean) – and if you consider the lack of global coverage on HadAT2 and RATPAC, giving those two a bit more error, you get an even tighter grouping. So, your inquisitor evidently is not aware of all of this evidence.

STAR’s current TMT trend (1979-2011) is +0.13 C/decade. To produce a lower tropospheric TLT value consistent with the fact the upper part of TMT is cooling (stratosphere) means the STAR TLT must be warmer than their TMT trend by around +0.07 or so, giving STAR a TLT trend of about +0.20 C/decade – well outside the range of independent observations.”

The IPCC AR4 (2007) discussed bulk tropospheric temperatures as an indicator of 5 atmospheric energy content. Here, we examine the latest publications about, and versions of, the AR4 data sets. The metric studied is the trend that represents the average rate atmospheric energy accumulation that relates to increased greenhouse gas forcing. For temperatures from microwave instruments, UAHuntsville’s indicates the lowest trend for 1979–2009 and NOAA-STAR’s the highest, being slightly 10 higher than Remote Sensing Systems’ (RSS). Updated analyses using radiosonde data suggest RSS and STAR experienced spurious warming after the mid-1990s. When satellite and radiosonde data sets are considered, the global trends for 1979–2009 of the lower and mid-troposphere are +0.15 and +0.06◦C decade−1 respectively. Error ranges of these estimates, if we do not apply information that 15 indicates some data sets contain noticeable trend problems, are at least ±0.05◦C decade−1, which needs reduction to characterize forcing and response in the climate system accurately.”

Great post, John, although I have to wonder why it never occurred to anyone to produce such a graph before now. Possibly because the trend is quite clear enough without it to anyone examining it with an unprejudiced eye? Unfortunately, people with a certain world view respond to things like this graph by just ignoring them, although we can hope that it will be persuasive for a few.

OTOH I suppose we may start seeing claims that the recent surfeit of La Ninas will exhibit persistence, such an argument being similar to ones raised about the PDO.

True, but the striking thing is that anthropogenic warming will overwhelm the El Niño-La Niña influence in just 13 years. Therefore even if the world goes into a permanent La Niña state (and there is no reason to believe it will), it will only hold back the warming temporarily – the La Niña years will still be as warm as the El Niño years of 13 years before.

[…] About the Lack of Warming… Using surface temperature data, John concludes that All else being equal, an El Niño year will average about 0.2 C warmer globally than a La Niña year. Each new La Niña year will be about as warm as an El Niño year 13 years prior. […]

You say: “the next El Niño will cause global temperatures to break their previous record”

I do see your point that we may get some more warming, and you may be right, but we are still well below the upper boundary for temperature over the past ten thousand years.

The previous record was set during the Medieval Warm Period. The next El Nino will not likely get close to breaking that record. In the mean time, the snows are building up and getting ready to advance the ice for the next several hundred years.

Hansen said in his 1981 paper in any case, that the CO2 signal would overcome all natural variability effects (i.e. solar cycle, ENSO, volcanoes) in the 1990s, so either Hansen was incorrect or the entire hypothesis is useless.

You know that you can’t just keep changing your mind about which dataset provider to use, which effects have caused global warming to stop, which time lags to apply etc. The science is supposed to be settled, yet you’re still generating new reasons for the lack of warming.

[J- I think Hansen’s statement is consistent with my “13 years of warming equals the difference between El Nino and La Nina” statement. – John N-G]

jdey123, I think you should not mistake the long-term climate forcings that Hansen discusses with the short term variability introduced by ENSO. In the paper you cite, and so nicely point out the relevant page, he points to a decrease in solar output of 0.6% per century, as well as a constant volcanic optical depth of 0.1 over the entire period. Neither are very likely, but both would be overwhelmed by the warming introduced by increasing CO2.

So far, 2012 has been colder than 2011. If you apply a 3 month time lag to the La Nina of 2011 in the 1st 3 months would be -1.5, -1.5, -1.5, whereas the 1st 3 months of 2012 is recorded as -0.8, -1.0, -1.0 so you’d expect 2012 to have been warmer.

The author seems to have completely ignored the solar cycle as well.

How many hypotheses does this settled science actually incorporate? Each scientist seems to make up their own hypothesis, and there’s a new one every few weeks.

Jdey, there’s no reason to expect monthly temperatures to correspond as tightly to the Oceanic Niño Index as you say. NG never denied that solar cycles affect global temperatures, he only showed how the warming trend can be seen under the ENSO variation. The paper he mentioned listed solar variation as am influence on temperature, but less so than ENSO or volcanic activity.

The “settled science” is that CO2 acts as a greenhouse gas and the Earth is warming. How much and how fast the Earth will warm is still being openly debated. The answer depends on how all of the factors that control climate interact.

Nice analysis Dr. N-G and excellent graphical presentation to illustrate your points. However, I wouldn’t use 30-40 year long data records to predict even the next 10 years of global temperature trends, when we know that approximately 62 year climate cycles exist, and were not considered in your analyis…. and when the last 40 year period was predominantly on the global temperature upswing of the last 62 year cycle that peaked in 2002. http://www.appinsys.com/globalwarming/SixtyYearCycle.htm

According to the first link above with all of its supporting data on existence of a 62 year cycle that also includes ENSO effects, we should expect a cooling effect from this cycle over the next 22 years of about 0.35 deg C from 2002 levels. Hopefully we can better understand causes of this longer term climate cycle over the next 22 years and use the results to make better predictions of net CO2 warming trends for the future.

John: You wrote in your post, “There aren’t that many full-blown El Niño events, but they seem to be following a steady upward trend. There are more La Niña events, and they too clearly follow a steady upward trend.”

The graph you referred to was not an ENSO index. It’s a graph of annual GISS LOTI data with ENSO events marked on it. So your statement above is erroneous and misleading, and served as the basis for many absurd comments from your visitors.

[Bob- Sorry, I’ll clarify the text. I meant: “There aren’t that many full-blown El Niño events, but global temperatures during El Niños seem to be following a steady upward trend. There are more La Niña events, and those global temperatures also clearly follow a steady upward trend.” – John N-G]

The global surface temperature anomalies in the years in which you’ve marked El Nino, La Nina and ENSO-neutral events have increased but you can’t say the events themselves are showing a trend, as you have. Also, are your confusing La Niña years with events? The La Niña event that lasted from 1998-2001 (1998-2000 using the ONI index) was one event, but you have multiple years marked. It also appears as though you missed part of an El Nino event. The 1986/87/88 El Nino was one of the strongest events in the latter part of the 20th Century, simply because it lasted from one ENSO season, through the summer, then into the second ENSO season. But I only see one year marked as an El Nino then on your graphs.

[The previous year (with the lag, that would be October 1986 through September 1987) came in with an average NINO 3.4 value of 0.44 C, just below the 0.5 C threshold. – John N-G]

BTW, how does your simple analysis account for the fact that major portions of the globe warm in response to major El Niño events AND in response to the La Niña events that follow them.

[It’s a global average. Your regional response may vary. – John N-G
]
ENSO is a process. It can’t be accounted for with an index, John. I’m not sure where that practice started, but it’s nonsensical.

[…] Texas State Climatologist and a Professor of Atmospheric Sciences at Texas A&M University, has a nice article published in the Houston Chronicle regarding the misconception that global warming has stopped based on global surface […]

“Further, a sharp observer would notice that Nielsen-Gammon found a creative way to eliminate the El Nino of 2009-2010 from his graphics. Very nice ploy. He gets creativity points. I’m not sure that’s what we’re looking for in our scientists, but look at him go!”

Except that adding 2010 to the list of El Nino years has almost no effect on the slope of the trend.

James switches tactics on his blog entry Does ENSO Alter Our Global Temps? OMG!!!LMAO!!!!, saying “Well, now what, people! ……. which is it? Was it just ENSO which created our global warming scare? If ENSO pulled the recent years down, …….. okay, let’s play along, the[n] explain this! Morons.”

He still is highly insulting, but James no longer claims El Nino years are left out. Instead he seems happy to ignore that ENSO is a repeating oscillation. Any change in climate caused by ENSO eventually reverses. James makes a big deal over the fact that a graph of the Oceanic Niño Index from 1970 – 1998 shows a positive slope, but had he graphed the ONI from 1970 to 2011 it would have shown the trend was flat.

[…] fair to say that global warming was part of the cause. Responsible climate scientists, such as the Texas State Climatologist say those things. Originally Posted by Mac-7 Besides attacking me is not going to make […]

It was clever to create the separated El Nino, neutral, and La Nina years, and there is of course warming for all three for the period examined. But I think it would be prudent to point out that the period examined does seem to correspond to most of the upward trending part of a longer term pseudo-oscillation, with a magnitude of +/- 0.1 C over ~60-65 year cycle. The first decade of the period you used to calculate the linear trends was still being impacted by Agung by somewhere near -0.05C to -0.1C. So a significant part of the upward trend from 1967 to present (up to ~0.3C out of ~0.7C) very well may not have been the result of Tyndall gas forcing. The remainder (0.4C – 0.45C) was most likely (indeed, almost certainly) due to that forcing. Whether the apparent ~60-65 year cycle continues to have influence on the temperature trajectory should become clear within about a decade, since the Earth should have entered the downward part of the cycle: warming should be slower over the next two decades than it was in the period you examined, in spite on rising Tyndall gas forcing.
.
I do not doubt there is Tyndall gas driven warming, but the true extent of that warming matters quite a lot in terms of appropriate public policy response. 0.45C over 45 years is significantly less alarming than 0.7C over 45 years.

[Steve – The rising temperatures are the net result of all forcing, not just Tyndall gas forcing, and include both positive and negative forcings. There is also a contribution from natural variability. However, until someone demonstrates that there’s a 60-65 year cycle IN THE RESIDUAL (i.e., that part of the variation of global temperatures that is not accounted for by the known forcings), I can’t regard it as a real phenomenon.

John,
There is no certainty that the apparent 60-65 year cycle is real, but the patern is consistent with a cyclical process. I have read several articles suggesting that this pattern shows up in the proxy recod as well (Chylek? Greenland ice cores.) The patern is not always there, but seems to be real for a at least a significant fraction of the record. I. Only urge some caution in assigning all the warming to greenhouse and related forcings.

With rgard to the influence of volcanoes it is pretty clear that the influence decays almost exponentially, but it does take quite a while, since the ocean response (and decay constant) is quite slow. I will try to send you a graphic or two over the weekend via email. The higher the assumed sensitivity, the longer the influence.

[…] the Lack of Warming… Posted on April 24, 2012 by Dan Moutal • 2 Comments John Nielsen-Gammon takes a look at claims that the mean surface temperature has stopped warming: There aren’t that many full-blown El Niño events, but they seem to be following a steady upward […]

[…] Texas State Climatologist and a Professor of Atmospheric Sciences at Texas A&M University, has a nice article published in the Houston Chronicle regarding the misconception that global warming has stopped based on global surface […]